here’s the question “skater A bumps into another skater, skater B. skater B is stationary. the skaters move off together in a straight line. explain what happens to the velocity of each of the skaters” PLS HELP

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?

Assume you measured the mass of the cart to be (500 ± 1) g and the mass of the additional mass you put on the cart to be (500 ± 1) g as well. since the scale you are using in the lab cannot measure objects heavier than 600g you will have to sum up individual pieces and propagate the error. so what would be the mass and the standard error of the cart and the mass

What is the role of lenses in microscopy?